Not that there is anything really wrong with what GM offers, but in my opinion you can do better on the heads and cam specs, and still have great driveability.
We have two popular cams, our
'545' cam and also our
Phoenix cam - both have excellent driveability, choppy idles, and lay down great numbers. With heads they do about 495-505rwhp on a dyno jet with cold air intake & headers.
I prefer to use Advanced Induction for the porting and polishing, they handle all of our porting for shop work and also when we spec mail order packages as well. He charges $995 for his full 280cc package.
We also sell
cam kits to go along with our cams, makes it easy as they include double valve springs (brian tooley), pushrods, all gaskets, timing chain, three bolt conversion kit, etc so no having to hunt everything down.
I would also suggest that you replace the oil pump (
Melling 10296) and it doesn't hurt to do a
comp trunion upgrade while you're in there. Let me know if you have any other questions. Also if you check out our Customer Build Blogs -
link - we put up a lot of pics, dyno sheets, and videos so you can get an idea of what to expect from our products.
PS saw you are from Fredonia - you don't ever see that name pop up too much on the forums! Great town.